The i360 towers over Brighton and Hove as construction nears completion.
Photograph: British Airways i360/ Visual Air

The newest structure on Brighton seafront is a tower only four metres in diameter – about the length of a family car. But its impact extends for miles along the coast of Britain’s most popular seaside destination.

The British Airways i360, a viewing tower that stretches up to the clouds, stands right next to the ruins of the West Pier. When an international team of workers downed tools, briefly, for the Christmas break they were ahead of schedule. The tower should be open in June and will transform the seafront.

The i360 will be advertised around the world. It will not only boost tourism, say prominent local residents and business leaders, it will send out a signal that one of Britain’s newest cities is open for business after a “lost decade”. The local council says it is the “catalyst for change for fitting out the seafront for the next 150 years”.

Others are horrified. Some locals say the height of the “doughnut on a hotdog sausage” will give planners more leeway to approve high-rise development that could lead to neighbouring Hove looking like Las Vegas or “being Benidormed”. The Victorian arches along much of the seafront will likely be lost during the wave of 21st-century developments.

New homes, a new conference centre, leisure facilities, more shops and tourist attractions are on the way, says the council. After decades of neglect, plans have been announced for a new conference centre near Brighton marina, with new development on the site of the current one. The project would cost more than £500m and is expected to be signed off early in 2016. And work is under way, or about to start, on two major seafront residential developments in Brighton Marina and Hove that will provide nearly 1,000 flats.

In a city that needs to build 30,000 homes by 2030, to reach targets set by the government, that will help. But more tall buildings are needed in a crowded city bounded by the sea and the South Downs National Park, and Brighton will have to look wider to enlist the help of neighbouring towns such as Newhaven, Lewes, Shoreham and Worthing.

“There is a general feeling that Brighton will build taller and increase population density,” says Gill Mitchell, Labour’s deputy leader of Brighton and Hove council, chairwoman of its environment group and leader of a panel that carried out an overview of the seafront, published last year, when work began on the i360. “We want to bring about lasting improvement.”

The i360 has been designed by the team that created the London Eye. Passengers will take “flights” in a pod that moves up and down the tower, from the top of which they will be able to see 26 miles in all directions – weather permitting. Diners at the on-site brasserie will order from a menu featuring produce that has been reared, grown, caught or created within that 26-mile radius.

Word is spreading fast, and the i360 will go global when it is advertised on BA flights bringing visitors to Britain. The entire site – which can cater for 1,000 – has already been booked by the Labour party for four days during its conference over the road at the Brighton Centre in September, 2017.

At 162m tall, Brighton’s new landmark will enter the Guinness Book of Records, says Eleanor Harris, who was commercial director of the London Eye before she became chief executive of the i360 nine years ago. “We are the world’s slenderest tall tower – nothing comes close to our height-to-diameter ratio of 40 to one,” says Harris. “We are also the tallest building in Sussex, and the world’s first vertical cable car.”

On one day last September, clouds were so low that the highest section of the tower, topped by a red light, appeared above them. It looked as though a rocket was being launched from the beach.

The city has helped with funding for the £46m project, most of which has been provided by the Public Works Loan Board. The target is for 739,000 customers every year, with visitors paying £15 and residents £7.50.

The “i” in its title stands for independence and innovation, says Harris, who worked closely with architects David Marks and Julia Barfield on the Eye and the i. Very appropriate for a city that is politically and culturally diverse – the three local MPs are Tory, Labour and Green, and there was no outright winner in the past four city elections – and has a reputation for quirkiness. But to one of its most notable residents Brighton & Hove has been held back by another “i” in the twenty-first century: indecision.

Development plans for Brighton’s King Alfred site, by architect Frank Gehry, fell through during the resort’s ‘lost decade’. Photograph: Nigel Bowles/Rex/Shutterstock

Sir Anthony Seldon, one of Britain’s foremost contemporary historians, wrote about Brighton and Hove in 2002, soon after city status was granted. In Brave New City, Seldon, who was leading Brighton College into a successful new era at the time, and convened many lively discussions about the city’s future, set out his “passionate advocacy of the need for progress”.

“Brighton and Hove is like no other city or seaside town in Britain or northern Europe,” he wrote. “It has evolved through eight eras of history… When it has been bold and imaginative it has been successful. When it has been safe and inward looking it has failed. Brighton and Hove must now move into a ninth era and become an international city or it will slip back again into the mediocrity that characterised so much of the postwar era.”

One legacy of that era was ugly buildings that blighted the seafront. There was talk in 2002 of imaginative new development along a seven-mile stretch of coast: Shoreham Harbour, the King Alfred site in Hove, the West Pier, the much maligned Brighton Centre and neighbouring cinema, the Black Rock site in east Brighton, and the marina.

There was political stasis, a recession, and none of it happened. The Victorian pier was lost to storm and fire. The Victorian Society recently highlighted the plight of the famous arches, which are unsafe and have been fenced off, causing an embarrassing eyesore. Chances of the council finding the £20m needed to restore them are nonexistent, with cuts beginning to bite. Frank Gehry, architect of Bilbao’s Guggenheim, was also a victim of the “lost decade” when his plans to redevelop the King Alfred site fell through. There was even a six-year delay – not the fault of city leaders – in the creation of the South Downs National Park, and, of course, there was the recession.

Seldon, now vice-chancellor of the University of Buckingham, looks back with disappointment. He is especially scathing about the recently departed Conservative-led coalition on the council and says there has been no strong leadership at any time this century.

“The i360 gives us more grounds for optimism, but Brighton has had a dismal time after city status,” he says. “You look at other cities and feel it has been a lost decade. There are so many incredible people in Brighton, so much creativity. The leadership has let down the whole city badly with its desperate lack of imagination. There has been a great loss of momentum.

“Not having Frank Gehry was a terrible mistake. There is no other city that’s as wacky culturally, and Britain needs a vital, creative, imaginative Brighton. We still need to be a Brave New City.”

But if all the talk came to nothing before, what are the chances of these big projects taking off now? “It will happen, it’s already happening,” says Mitchell.

“You need a catalyst for change and the i360 is providing it. We are talking to developers, we will explore every avenue for funding, and we are fitting the seafront for the next 150 years. We want an improvement in the seafront vision by 2020. It won’t look like Benidorm or Las Vegas. It will look like Brighton – a new Brighton.”

I’m on the board of the West Pier Trust and I am in favour of the i360. I also love the ruin of the West Pier, which has become one of the emblems of the city.

A lot of seafront projects have not happened but for the i360 the building work has been very swift and it’s all on time or ahead of schedule. That’s most unusual. I don’t think Brighton’s ever had anything built on time before.

Scott Marshall, Brighton & Hove Council director for culture, regeneration and housing 1999-2010, now runs a company specialising in urban regeneration

In the mid-1990s to mid-2000s the big investors wanted out-of-town retail sites but the seafront is the city’s biggest asset. Brighton became a bit cocksure after it got city status. It is probably the only city in the world ever to have asked Frank Gehry to compete against other architects for a commission [King Alfred]. He won but there were delays and the financial backers pulled out. If that development had gone ahead it would have put Brighton & Hove on an international map that it’s currently not on.

Until there is a single strong leadership of any political party – and developers don’t care whether that’s blue or red or green – the city will always be in a state of limbo

This is a fantastic place to live, work and visit but it does have a reputation for being difficult to develop in. The seafront is very important for tourism and that provides about 20% of the local economy. However, there has been scant investment in the seafront. Little art galleries and cafes, yes, but nothing has been done for the engineering. It’s beautiful, elegant, Victorian, but it’s not safe and it’s not open.

The cost of repairing the Victorian arches could be too high. The days when councils could spend that sort of money [estimated £20m] on that sort of thing are long gone.

There is a case for saying let the arches go, and replace them with something else. But that would be hugely controversial.

Look at Portsmouth’s Spinnaker Tower – it has transformed the image of the city.

I don’t hear a lot of flattering comments about the i360, but Brighton is built around an outlandish building, the Royal Pavilion. It’s an innovation and people here are generally dynamic and interested in new things.

I’ve heard it said that Brighton is the place where young people come to retire. Many businesses are not interested in growth, they just want sustainability, to be able to retain their lifestyle. Whether that’s good or bad for Brighton, who can say?

Glynn Jones, chair of West Pier Trust, chief executive of Brighton Borough Council before city status

Without the i360 the West Pier Trust would have been dead in the water years ago. We are the landowners and they are our tenants. Once it was burned down a second time [2003] the West Pier became a building that could not be restored.

In the longer term the i360 funding will help us to determine whether there is interest in developing a new pier. A replica Victorian pier would be wrong. A state-of-the-art, modern pier with a daring design is right for the 21st century, just as Eugenius Birch’s West Pier was 150 years ago.

There are always people who don’t want development, who object to new designs; there were objections to the West Pier back in the 1860s.

The seafront is Brighton’s shopfront. We [Brighton council under Lord (Steve) Bassam’s Labour leadership] regenerated the area between the two piers in the 90s, a brave decision. Until then, no council had ever invested any money in the seafront (the original outlay was £1m).

The i360 is the last piece of that work, completing a “string of pearls” from the Palace Pier to the site of the i360. There is an artist’s quarter, a restaurant quarter, a club quarter and an outdoor activity quarter – and now the i360.

The i360 is iconic, and represents the best of design, and getting it up and running is a signal to developers. The work going on at the marina would never have happened but for the i360.

Warren Morgan, Leader, Brighton & Hove council

I believe there is no seaside town or city in the country where more seafront investment is already underway or planned. Visitor numbers are growing year on year [around 11 million a year].

We are moving forward with plans to redevelop the Brighton Centre-Kingswest site and to build a new King Alfred leisure centre and a new swimming facility. This all takes time because councils no longer have the money to act alone and must work in complex partnerships with developers.

Eleanor Harris, chief executive, British Airway i360

Tickets will be half price [£7.50] for residents, and every child in a state school in Brighton & Hove will get a free entry during their school years.

There can be a bit of a separation between locals and tourists and we want the i360 to be for both. We want the population of Brighton to feel that the i360 is theirs.